1. Field of the Invention
The present invention disclosed herein relates to a street lamp control system, and more particularly, to a wireless communication based safer street lamp control system which cuts off power sources around a street lamp where an electric leakage or dangerous situation occurs among street lamps and allows the rest street lamps to be turned on, and a remote street lamp control system using a Zigbee technique having a transmission distance of about 100 m.
2. Description of the Prior Art
A street lamp system currently employed (by most autonomous entities) has a distribution panel A with one or two electric circuit breakers therein in accordance with whether every other street lamp is turned on as shown in FIG. 1, thereby controlling turning-on/off of the whole street lamps.
When an electric leakage or other problems on safety and function occur even on any one of the street lamps, a power source is collectively cut off all lamps of right or left section in FIG. 1, which are a series of street lamps connected to the abnormal street lamp, so that these street lamps could not perform the respective functions of illumination.
As a result, the loss of illumination causes the passages of vehicles and people passing by the corresponding street lamps to occur many dangers and obstacles.
Meanwhile, a plurality of street lamps are generally connected to a line branched off from the distribution panel. The existing street lamp control system is configured to cut off the power source from the whole street lamps even when any one of the installed street lamps is out of order due to an electric leakage or the like.
Recently, power line communication technique as one of communication methods are employed for controlling these street lamps.
It is however impossible for power line communication technique to control street lamps when an electric leakage occurs. The electric leakage causes power to be cut off from the street lamp to which the electric leakage occurs, and there are no communication channel when the electric leakage occurs.
It is a similar case for the case of submerging. If cable is submerged and there are parallel current path, then most of signals flow through water to return path, not through load to return path because water has low impedance and this also makes difficult to communicate.
Accordingly, the power line communication scheme cut off the power source of the distribution panel connected to street lamps in an area group where the abnormal street lamps belongs when a dangerous factor on safety including an electric shock or a malfunction occurs on the street lamp so that the only group control of turning off the street lamps can be implemented, however, the individual control for the abnormal street lamp can not be implemented.